1. Field of the Invention
This invention relates to a tree treatment capsule for feeding a chemical agent into plants and in particular to a capsule for delivering a chemical agent to the phloem layer of a tree. The chemical agent may be either a herbicide or any other tree destroying agent if the treatment is designed to kill the tree, or a fungicide or other medicant or nutrient if the treatment is designed to cure the tree from a decease or a deficiency.
2. Description of the Prior Art
The prior art relating to implantation treatment of trees involves either injection of a cartridge into the tree without preparing a pre-drilled hole in the tree, or implantation of a capsule in a pre-drilled hole in the tree. Examples of prior art devices for such treatment are set forth below.
U.S. Pat. No. 3,691,683 discloses a cartridge containing a chemical liquid agent where the cartridge is hammered into a tree so that it fractures upon impact. However, the cartridge is inserted only half-way in the tree. Therefore, upon fracture, much of the liquid agent is wasted on the surface of the tree, where it also presents a hazard to the person making the injection.
U.S. Pat. No. 4,308,689 discloses a tree treatment capsule for insertion into a pre-drilled hole in a tree. The capsule is made of a frangible material and contains a liquid agent so that an impact force applied to an end cap of the capsule causes breaking of the capsule. This known capsule is disadvantageous since it begins to break near the bore opening. The capsule thus presents the risk that the liquid agent will be exposed outside the bore opening. The end cap of the known capsule also requires a very complicated structural design which renders the capsule expensive to manufacture